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<div class="titlepage"><div><div><h4 class="title">
<a name="boost_asio.reference.ssl__stream.async_read_some"></a><a class="link" href="async_read_some.html" title="ssl::stream::async_read_some">ssl::stream::async_read_some</a>
</h4></div></div></div>
<p>
          <a class="indexterm" name="boost_asio.indexterm.ssl__stream.async_read_some"></a> 
Start
          an asynchronous read.
        </p>
<pre class="programlisting">template&lt;
    typename <a class="link" href="../MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a>,
    typename <a class="link" href="../ReadHandler.html" title="Read handler requirements">ReadHandler</a> = <a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a>&gt;
<a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.automatic_deduction_of_initiating_function_return_type"><span class="emphasis"><em>DEDUCED</em></span></a> async_read_some(
    const MutableBufferSequence &amp; buffers,
    ReadHandler &amp;&amp; handler = <a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a>);
</pre>
<p>
          This function is used to asynchronously read one or more bytes of data
          from the stream. The function call always returns immediately.
        </p>
<h6>
<a name="boost_asio.reference.ssl__stream.async_read_some.h0"></a>
          <span class="phrase"><a name="boost_asio.reference.ssl__stream.async_read_some.parameters"></a></span><a class="link" href="async_read_some.html#boost_asio.reference.ssl__stream.async_read_some.parameters">Parameters</a>
        </h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl class="variablelist">
<dt><span class="term">buffers</span></dt>
<dd><p>
                The buffers into which the data will be read. Although the buffers
                object may be copied as necessary, ownership of the underlying buffers
                is retained by the caller, which must guarantee that they remain
                valid until the handler is called.
              </p></dd>
<dt><span class="term">handler</span></dt>
<dd>
<p>
                The handler to be called when the read operation completes. Copies
                will be made of the handler as required. The equivalent function
                signature of the handler must be:
</p>
<pre class="programlisting">void handler(
  const boost::system::error_code&amp; error, // Result of operation.
  std::size_t bytes_transferred           // Number of bytes read.
);
</pre>
<p>
              </p>
</dd>
</dl>
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<h6>
<a name="boost_asio.reference.ssl__stream.async_read_some.h1"></a>
          <span class="phrase"><a name="boost_asio.reference.ssl__stream.async_read_some.remarks"></a></span><a class="link" href="async_read_some.html#boost_asio.reference.ssl__stream.async_read_some.remarks">Remarks</a>
        </h6>
<p>
          The async_read_some operation may not read all of the requested number
          of bytes. Consider using the <a class="link" href="../async_read.html" title="async_read"><code class="computeroutput">async_read</code></a>
          function if you need to ensure that the requested amount of data is read
          before the asynchronous operation completes.
        </p>
<h6>
<a name="boost_asio.reference.ssl__stream.async_read_some.h2"></a>
          <span class="phrase"><a name="boost_asio.reference.ssl__stream.async_read_some.per_operation_cancellation"></a></span><a class="link" href="async_read_some.html#boost_asio.reference.ssl__stream.async_read_some.per_operation_cancellation">Per-Operation
          Cancellation</a>
        </h6>
<p>
          This asynchronous operation supports cancellation for the following <a class="link" href="../cancellation_type.html" title="cancellation_type"><code class="computeroutput">cancellation_type</code></a>
          values:
        </p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
              <code class="computeroutput">cancellation_type::terminal</code>
            </li>
<li class="listitem">
              <code class="computeroutput">cancellation_type::partial</code>
            </li>
</ul></div>
<p>
          if they are also supported by the <code class="computeroutput">Stream</code> type's <code class="computeroutput">async_read_some</code>
          and <code class="computeroutput">async_write_some</code> operations.
        </p>
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      M. Kohlhoff<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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